JUPITER AT OPPOSITION: Tonight, Dec. 2-3, Jupiter is at opposition--that is, Earth passes between the sun and Jupiter. Jupiter rises at sunset and soars overhead at midnight. Jupiter is the largest planet in our solar system and it shines more brightly than any star in the night sky.

There is no better time to look at the giant planet, because this is the closest opposition of Jupiter until the year 2021. [more]

One thousand Earths could fit inside Jupiter. Image credit: NASA

THE SCALE OF AMAZING: A slow but dense solar wind stream is buffeting Earth's magnetic field, igniting bright auroras around parts of the Arctic Circle. "Wow!" says Fredrik Broms of Kvaløya, Norway. "On the scale of amazing, the sky went from 0 to 100 in only five minutes." He took this picture on Dec. 1st:

"The sky has been clear for several days without a trace of any auroras here in the north, but tonight all this changed in an instant," he adds. "I witnessed one of the most powerful auroras in a long while with an exceptionally distinct band of purple-pink from excited nitrogen molecules at the lower edge. A wonderful start of December!" More auroras could be in the offing as Earth penetrates this stream of solar wind, which is flowing from a coronal hole on the sun. NOAA forecasters estimate a 20% chance of high-latitude geomagnetic activity. www.spaceweather.com